Depending on whether you manage yourself or hire property management, your return on equity seems very strong for having no debt on the properties. If you are paying a property manager and still generating $84,000 cashflow on $800,000 equity, your return on equity is over 10%.
If you think that you can generate a lot more cashflow relative to the amount of equity in other investments, then I would consider selling and doing a 1031 exchange into larger property(ies). I just did this with a duplex and bought a 6-unit property in my market. Long story short, I had $150K equity in the duplex (due to appreciation) and was cashflowing very little - $5,000 per year. So my return on equity on equity was 3.33% ($5,000 / $150,000). I sold the duplex and bought a 6-unit property that will generate over $15,000 per year in cashflow, which is over a 10.00% return on equity ($15,000+ / $150,000). Even with the higher rates, I am able to generate a lot more cashflow from that same amount of equity.